Spring clips and snap rings are well known examples of a family of mechanical devices made of an elongated material such as metal or plastic that is formed into a loop that is inelastic along the length of the loop and elastic when force is applied transverse to the loop. U.S. Pat. No. 6,149,206 of J. DiRocco shows two types of such devices: FIG. 1 shows an external clip with spaced members that spread apart while being applied and then spring back to a resting position within slots on the exterior of a cylinder. FIG. 3 shows an internal clip with spaced members that compress while being applied and then spring back to a resting position within a slot on the interior of a cylinder. External force is applied to each of these clips while they are transitioning from the applied state within a slot to being disconnected from the slot. The clips are not under tension when in normal use.
The particular application for which this invention is designed is to clamp two tubes together at their ends. One typical way of accomplishing this task is with a V-band, or Marman, clamp that encircles abutting exterior flanges on each tube with a V-shaped member on the interior surface of the clamp. A tensioning device holds the clamp tightly against the flanges. The exterior V-band clamp cannot be used in underground and similar environments where the exterior surface of the tubes is tightly surrounded by earth or other medium.
U.S. Pat. No. 6,269,748 of E. Rudoy et al discloses a triggering mechanism for a V-band clamp that enables a small force to release the clamp.
U.S. Pat. No. 5,464,147 of N. Miknami discloses an internal clamp for aligning two large cylinders together for welding by expanding a ring with compressed air against the inside edge of two abutting cylinders. Coil springs retract the clamp after the air is released.